Vapor–liquid equilibria and excess properties of octane + 1,1-dimethylpropyl methyl ether (TAME) mixtures

Vapor–liquid equilibrium (VLE) data are reported for the binary mixtures formed by octane and the branched ether 1,1-dimethylpropyl methyl ether (tert-amyl methyl ether or TAME). A Gibbs–van Ness type apparatus was used to obtain total vapor pressure measurements as a function of composition at 298.15, 308.15, 318.15 and 328.15 K. The system shows positive deviations from Raoult’s law. These VLE data are analyzed together with data previously reported for octane+TAME mixtures: VLE data at 323.15 and 423.15 K, excess enthalpy (HmE) data at 298.15 and 313.15 K and excess volume (VmE) data at 298.15 K. The UNIQUAC model, the lattice–fluid (LF) model, and the Flory theory are used to simultaneously correlate VLE and HmE data. The two latter models are then used to predict VmE data. The original UNIFAC group contribution model and the modified UNIFAC (Dortmund model) are used to predict VLE data.